NFS: Switch from intr mount option to TASK_KILLABLE

By using the TASK_KILLABLE infrastructure, we can get rid of the 'intr'
mount option.  We have to use _killable everywhere instead of _interruptible
as we get rid of rpc_clnt_sigmask/sigunmask.

Signed-off-by: Liam R. Howlett <howlett@gmail.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>

include/linux/nfs_fs.h

@@ -516,14 +516,7 @@ extern void * nfs_root_data(void);
 
 #define nfs_wait_event(clnt, wq, condition)				\
 ({									\
-	int __retval = 0;						\
-	if (clnt->cl_intr) {						\
-		sigset_t oldmask;					\
-		rpc_clnt_sigmask(clnt, &oldmask);			\
-		__retval = wait_event_interruptible(wq, condition);	\
-		rpc_clnt_sigunmask(clnt, &oldmask);			\
-	} else								\
-		wait_event(wq, condition);				\
+	int __retval = wait_event_killable(wq, condition);		\
 	__retval;							\
 })